It is known that the primary (linear amino acid) sequence of a protein determines its three-dimensional (tertiary) structure. Potential functions have been developed that can be used to compute reliably the energies of any conformation of a given molecule especially in cases where solvation effects are negligible, as is the case for membrane proteins which require a low dielectric medium to insure proper folding. We have developed a method using these potential functions that allows for the computation of the three-dimensional structures of such proteins from their amino acid sequences and have applied it to the structures of leader sequences that cause transport of proteins across membranes and to the structure of the membrane- active protein, melittin.